TypeError:无法读取未定义的属性“msg”

Question

app.js

const express = require("express");
const bodyParser = require("body-parser");
const ejs = require("ejs");

const app = express();

app.set(bodyParser.urlencoded({extended:false}));
app.set('view engine', 'ejs');
app.use(express.static('public'));

var blogName = "";

app.get("/", function(req, res){
    blogName = "Priyanshu Gupta's Not-So-Secret Diary";
    res.render("index", {titleName : blogName});
})
app.get("/about", function(req, res){
    blogName = "About This Blog";
    res.render("about", {titleName : blogName});
})
app.get("/contact", function(req, res){
    blogName = "Contact Me";
    res.render("contact", {titleName : blogName});
})

app.get("/blog", function(req, res){
    blogName = "Blog Post";
    res.render("blogPage", {titleName : blogName})
})

app.get("/compose", function(req, res){
    res.render("compose")
})

app.post("/contact", (req, res) => {
    console.log(req.body.msg);
})

app.listen(3000, function(){
    console.log("Your server is running on port 3000!");
})

我在代码中使用了express，得到的错误如下

TypeError：无法读取未定义的属性'msg'at F：\Priyansh\Coding Playground\Web Development\Blog\app.js:36： 26 at Layer.handle[作为handle_request]（F：\Priyantu\Coding Playground\Web Development\Blog\node_modules\Express\lib\router\layer.js:95： 5）在下一个（F：\Priyansh\Coding Playground\Web Development\Blog\node_modules\Express\lib\router\route.js:137： 13）在Route.dispatch（F：\Priyansh\Coding Playground\Web Development\Blog\node_modules\Express\lib\router\route.js:112： 3）在Layer.handle[作为handle_request]（F：\Priyansh\Coding Playground\Web Development\Blog\node_modules\Express\lib\router\layer.js:95： 5）at F：\Priyansh\Coding Playground\Web Development\Blog\node_modules\Express\lib\router\index.js:281： 22 at Function.process_params（F：\朴雅树\Coding Playground\Web Development\Blog\node_modules\Express\lib\router\index.js:335： 12）在下一个（F：\朴雅树\Coding Playground\Web Development\Blog\node_modules\Express\lib\router\index.js:275： 10）在serveStatic（F：\朴雅树\Coding Playground\Web Development\Blog\node_modules\服务静态\index.js:75： 16）在Layer.handle[作为handle_request]（F：\Priyansh\Coding Playground\Web Development\Blog\node_modules\Express\lib\router\layer.js:95： 5）

联系html

<%- include('header') %>

<div class="container mt-4">
    <h1 style="text-align: center;">Contact Me</h1>
    <form action="/contact" method="POST">
      <div class="mb-3">
        <label for="email" class="form-label">Email address</label>
        <input type="email" name="email" class="form-control" placeholder="[e-mail]" autocomplete="off">
      </div>
      <div class="mb-3">
        <label for="msg" class="form-label">Example textarea</label>
        <textarea class="form-control" name="msg" rows="3" style="margin-top: 0px; margin-bottom: 0px; height: 224px;" required></textarea>
      </div>
      <button type="submit" class="btn btn-success mb-4">Submit</button>
    </form>
</div> 
<%- include('footer') %> 

正文解析器无法检测到联系人表单中的msg，请任何人都找出我在这里面临的问题是什么

Answer 1

您忘记了标题application/jsonHTML表单不支持它，因此需要一种解决方法。我建议将其与fetchapi一起使用，然后发布数据或其他信息。如果是这样，我仍然没有100%的信心，但是试着这样做。

Answer 2

超文本标记语言文件中的数据已成功发送，但app.js无法解析请求正文。为了将数据解析成JSON文件，应该正确使用主体解析器。当服务器文件按结构划分时，每个. js文件都应该使用body解析器。

app.use(bodyParser.json());
app.use(bodyParser.urlencoded({extended:false}));

js prettyprint-override">const express = require("express");
const bodyParser = require("body-parser");
const ejs = require("ejs");

const app = express();

app.set(bodyParser.urlencoded({extended:false}));
app.set('view engine', 'ejs');

//app.use(express.static('public'));

/// try this
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({extended:false}));

var blogName = "";

app.get("/", function(req, res){
    blogName = "Priyanshu Gupta's Not-So-Secret Diary";
    res.render("index", {titleName : blogName});
})
app.get("/about", function(req, res){
    blogName = "About This Blog";
    res.render("about", {titleName : blogName});
})
app.get("/contact", function(req, res){
    blogName = "Contact Me";
    res.render("contact", {titleName : blogName});
})

app.get("/blog", function(req, res){
    blogName = "Blog Post";
    res.render("blogPage", {titleName : blogName})
})

app.get("/compose", function(req, res){
    res.render("compose")
})

app.post("/contact", (req, res) => {
    console.log(req.body.msg);
})

app.listen(3000, function(){
    console.log("Your server is running on port 3000!");
})